1. Field of the Invention
The present invention relates to a Universal Serial Bus (USB) connector and, more particularly, to a USB connector used in Universal Serial Bus 3.0 (USB 3.0) specification.
2. Description of the Related Art
Universal Serial Bus has been the most popular interface in signal transfer among a variety of electronic devices. Specifically, USB has been commonly used to transfer signals among peripheral devices for computers and digital audio-visual equipments, such as keyboards, mice, flash drives and card readers.
The USB specification has been upgraded from version 1.0 (proposed in 1996) to version 2.0, then further to version 3.0 in 2008. In contrast to USB 2.0 which uses a pair of power lines and a pair of differential data wires to transfer signals in half duplex operation, USB 3.0 uses two pair of signal wires and a ground wire to transfer signals in full duplex operation. One pair of signal wires is adapted to transfer signals and the other pair of signal wires is adapted to receive signals, thereby separating the data transmission and acknowledgement processes. This allows USB 3.0 to reach a data transfer rate as high as 4.8 Gbps which is ten times faster than USB 2.0. USB 3.0 relatively has a larger amount of conducting terminals compared to USB 2.0.
A conventional USB connector generally includes an insulating base, a plurality of conducting terminals and a circuit board. The insulating base has a plurality of grooves. The circuit board mounted in the insulating base has a plurality of electrical contacts. Each conducting terminal is mounted in the corresponding groove and connects with the corresponding electrical contact of the circuit board. During the manufacturing process of the USB connector, the plurality of conducting terminals is inserted into the grooves of the insulating base one by one, and melting plastic is then injected into the grooves of the insulating base. In this manner, the USB connector is integrally formed after the plastic cools down. By applying such fabrication process, each conducting terminal forms a point of contact with the corresponding electrical contact, allowing the conducting terminals of the USB connector to be coupled with the insulating base by way of adhesion.
However, once the machines breakdown or the materials on the conveyer experience undesired shifts in position during the manufacturing process of the conventional USB connector, the conducting terminals are placed in wrong positions, which locate the contacts between the conducting terminals and the circuit board incorrectly. As a result, the USB connector has an unstable signal transmission or even has no signal transmission capability when the conducting terminals are connected to the insulating base. In particular, since USB 3.0 has a larger amount of conducting terminals, it is likely that the USB connector has a low yield rate after the conducting terminals are coupled with the insulating base by adhesion, which creates the extra manufacture cost and the waste of materials. Furthermore, the points of contact between each conducting terminal and the circuit board form a structure with weak stability. If the USB connector experiences a collision, it is likely to cause problems such as difficulty in reading the data, affecting the transmission quality and causing inconvenience in use.
In addition, the conducting terminals are inseparably secured on the insulating base. For a defective USB connector, even if only one of the conducting terminals is marked as a bad contact during testing, the entire insulating base and the other conducting terminals have to be abandoned, also increasing the manufacture cost.